Sherlock season 4: Dad's Army star Toby Jones will play 'iconic' villain from Conan Doyle books

Beloved British actor Toby Jones is to play a "truly iconic" Sherlock Holmes villain in the upcoming fourth season of the BBC's hit contemporary adaptation of the famed detective. "I'm delighted to have Toby Jones on board, bringing to life one of (Arthur Conan) Doyle's finest villains," said showrunner Steven Moffat.

Jones, who is famous for his roles in Frost/Nixon, The Hunger Games, and the first two Captain America films, will be making his debut in the detective series in the second and third episodes of the fourth season.

Speaking about his casting in the globally popular TV series, the 49-year-old actor said: "I'm excited and intrigued by the character I shall be playing in Sherlock." Jones will appear in the series' second and third episodes.

As fans have come to expect, show bosses are closely guarding any and every detail related to the anticipated episodes and haven't yet disclosed which of Doyle's legendary villains will be portrayed by Jones.

Jones has had a long and varied career highlighted by roles in acclaimed horror Berberian Sound Studio, the Harry Potter series (as the voice of Dobby) and more recently British comedy adaptation Dad's Army.

Sherlock's co-creator Mark Gatiss, who plays the role of Sherlock's brother Mycroft Holmes in the series, was thrilled to welcome the Hollywood prodigy, saying: "I know Toby will embrace the part with true relish!"

Episode 2 directed by Emmy-nominated Nick Hurran is currently filming. The fourth season of Sherlock is expected to return to BBC One in early 2017.